Inspiron 17R SE 7720 - Raid 1

I have a 17R SE 7720 with two 1 TB hdds and i am trying to mirror the disks as a raid 1 using iRST. iRST is selected in the BIOS and even caching with an msata SSD (shown as Raid 0) works fine. Anyway, the iRST tool does not offer to create a new volume. Any Ideas why?

to the best of my knowledge the 7720 only has 1 sata III (6gb/s) port on the motherboard thus making raid virtually impossible employing sata III ( 6gb/s) however the motherboard does have multiple sata II (3gb/s) ports that could be used for raid both drives should be running at same speed for raid hope this helps good luck